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Status and Prospects of SuperKEKB and Belle II. July 24, 2010 Yutaka USHIRODA (KEK ) for the Belle II Collaboration. The last beam abort of KEKB on June 30, 2010. First physics run on June 2, 1999 Last physics run on June 30, 2010 L peak = 2.1x10 34 /cm 2 /s L > 1ab -1. Physics.
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Status and Prospects of SuperKEKB and Belle II July 24, 2010 Yutaka USHIRODA (KEK) for the Belle II Collaboration
The last beam abort of KEKB on June 30, 2010 First physics run on June 2, 1999 Last physics run on June 30, 2010 Lpeak = 2.1x1034/cm2/s L > 1ab-1
Physics Future Measurements: Precision frontier / Energy frontier Flavor Factories / LHC complementary quest for New Physics Super B factories: O(102) larger Ldt NP scale reach: Current Measurements: - Omissions in SM (possible in SM): e.g. “new spectroscopy” y’ Z+(4430) X(3872) Belle, PRL 91, 262001 (2003), 140fb-1 Belle, PRL 100, 142001 (2008), 605fb-1 - Hints of discrepancies with SM (impossible in SM): Belle II, Technical Design Report, in preparation direct measurements CKM Fitter DØ, arXiv:1005.2757 indirect fit to other observables - Minimal Flavor Violation - Enhanced flavor violating couplings B(B →tn), ASLB, ...
Physics with 50ab-1 “bread & butter”: - B factory: B →J/y KS, B ~ 4.5∙10-4 dS ~0.03 - Super B factory: B →K*g, B ~ 4.0∙10-5 dS ~0.2 g ~a few % Interesting modes for NP: - B factory: B →Kp, B ~ 1.9∙10-5 - Super B factory: B →Knn, B ~ 4∙10-6 5 ab-1 50 ab-1 CKM Fitter adopted from HFAG Theory 50 ab-1 Belle, Nature 452, 332 (2008), 480 fb-1 adopted from W. Altmannshofer et al., JHEP 0904, 022 (2009) S(KSp0g), Knn, tn, … are not possible @ LHCb
SuperKEKB collider Contribution ID: 561 The SuperKEKB accelerator status e+4GeV 3.6 A Colliding bunches Belle II New IR e-7GeV 2.6 A New superconducting /permanent final focusing quads near the IP SuperKEKB New beam pipe & bellows Replace short dipoles with longer ones (LER) Add / modify RF systems for higher beam current Low emittance positrons to inject Positron source Damping ring Redesign the lattices of HER & LER to squeeze the emittance New positron target / capture section Low emittance gun TiN-coated beam pipe with antechambers Low emittance electrons to inject Target: L = 8x1035/cm2/s
Luminosity upgrade projection Milestone of SuperKEKB We will reach 50 ab-1 in 2020~2021. 9 month/year 20 days/month Integrated Luminosity (ab-1) Commissioning starts mid of 2014 Peak Luminosity (cm-2s-1) Shutdown for upgrade Year Y. Ohnishi
Beam Background BKG/BKG(2003) Background composition derived from background study data, which is then scaled by Luminosity, beam current etc. x10 to x20 as large background as that of 2003 conditions (~severest) Similar or Higher detector performance even under x20 bkg
Belle II Detector (in comparison with Belle) SVD: 4 DSSD lyrsg 2 DEPFET lyrs + 4 DSSD lyrs CDC: small cell, long lever arm ACC+TOF g TOP+A-RICH ECL: waveform sampling (+pure CsI for end-caps) KLM: RPC g Scintillator +MPPC(end-caps) Parameters are preliminary
Outline • Introduction • Status of Detector Development • Beam Pipe, Vertex Detectors, Particle ID, … • Status and prospects of the Project • Summary & Conclusion
IP Chamber version 2010/07/01 20mmf Collimate the SR here (Beam pipe diameter is 9mm) HER beam LER beam Special thanks to M. Sullivan(SLAC) as TDR review committee member who pointed out the SR issue.
Tests Mechanical mock-up Cooling Test
Vertex Detector DEPFET: http://aldebaran.hll.mpg.de/twiki/bin/view/DEPFET/WebHome Beam Pipe r = 10mm DEPFET Layer 1 r = 14mm Layer 2 r = 22mm DSSD Layer 3 r = 38mm Layer 4 r = 80mm Layer 5 r = 115mm Layer 6 r = 140mm Mechanical mockup of pixel detector Prototype DEPFET pixel sensor and readout A prototype ladder using the first 6 inch DSSD from Hamamatsu has been assembled and tested.
Expected performance Ks track p+ p- g g B vertex IP profile g Significant improvement in IP resolution! Pixel detector close to the beam pipe Belle s[mm] s[mm] BelleII’ BelleII 20mm 10mm 0 1.0 2.0 0 1.0 2.0 B decay point reconstruction with KS trajectory pbsin(q)3/2[GeV/c] pbsin(q)5/2[GeV/c] Significant improvement in dS(KSp0g) Less Coulomb scatterings Larger radial coverage of SVD
Particle Identification Devices Endcap PID: Aerogel RICH (ARICH) Barrel PID: Time of Propagation Counter (TOP) Quartz radiator Focusing mirror Small expansion block Hamamatsu MCP-PMT (measure t, x and y) 200mm Cherenkov photon Aerogel radiator Aerogel radiator n~1.05 Hamamatsu HAPD + readout 200 Hamamatsu HAPD + new ASIC
TOP (Barrel PID) [1count/25ps] [1count/25ps] • Quartz radiator • 2.6mLx 45cmWx 2cmT • Excellent surface accuracy • MCP-PMT • Hamamatsu 16ch MCP-PMT • Good TTS (<35ps) & enough lifetime • Multialkali photo-cathode SBA • Beam test done in 2009 • # of photons consistent • Time resolution OK 1st 1st 3rd 3rd 2nd 2nd Time resolution quartz beam data Beam spot Simulations 2nd 915mm 3rd 1st 875mm # of photons
Aerogel RICH (endcap PID) Contribution ID: 1016 Aerogel RICH for Belle II Test Beam setup Aerogel Clear Cherenkov image observed Hamamatsu HAPD Q.E. ~33% (recent good ones) Cherenkov angle distribution RICH with a novel “focusing” radiator – a two layer radiator Employ multiple layers with different refractive indices Cherenkov images from individual layers overlap on the photon detector. 6.6σp/K at 4GeV/c !
Other design & development activities Intensively going on!
Funding Status KEKB upgrade has been approved • 5.8 oku yen for Damping Ring (FY2010) • 100 oku yen for machine -- Very Advanced Research Support Program (FY2010-2012) Continue efforts to obtain additional funds to complete construction as scheduled.
Construction Schedule of SuperKEKB/Belle II Jun. 24, 2010 FY2009 FY2010 FY2011 FY2012 FY2013 FY2014 e+ new matching & L-band acc. Linac R&D Construction e+ beam commissioning RF-gun & laser system A1 gallery extension move to A1 Design study Commissioning at test stand e- beam commissioning Damping Ring Facilities Tunnel construction DR commissioning Building construction Components R&D, Design Mass Fabrication Installation Main Ring Facilities Building construction Components MR commissioning R&D, Design Mass Fabrication Installation BEAST II Belle II Detector Ad-hoc detector for MR commissioning R&D Mass Production Construction Belle roll-out in Dec. 2010 Installation (KLM) Installation (E-cap) • Ready to Roll-in Installation (Barrel) • Cosmic Ray Test
Belle II Collaboration http://belle2.kek.jp 13 countries/regions, 53 institutes
Summary and Conclusion • SuperKEKB/Belle II aims for (discovering and) understanding the New Physics. • Target Luminosity of SuperKEKB is 8x1035/cm2/s, will provide 50ab-1 by 2020-2021. • Belle II gives similar or better performance than Belle even under ~20 times higher beam background. • Project has been approved by Japanese Government in June 2010. KEKB/Belle operation has been willingly terminated. Construction starts shortly. • Next collaboration meeting: Nov. 17-20 @KEK, still open to everyone. • Technical Design Report will be printed very soon.
Peak Luminosity History and Prospects 40 times higher Next generation B-factories 50 ab-1can be accumulated withinseveral years. E.Kikutani / M. Masuzawa
Synchrotron Radiation QC2 BL1 QC1 QC3
Central Drift Chamber longer lever arm improve resolution of momentum and dE/dx small cell normal cell 18 mm 10 mm 10~20 mm 6~8 mm
Test Chambers X-t relation (B=0T) Residual distribution ASIC AMP/discriminator 8ch/chip FADC Drift time [nsec] position resolution σ ~ 100μm high speed data link dE/dx resolution 12% with “9” layers 5% with 56 layers FPGA (TDC) 90 60 30 [degree] 90 60 30 [degree] [mm] distance from sense wire [mm] Prototype readout board (will be placed behind the detector) Test Beam Results with 5 Layer Test Chamber SiTCP for CDC test Yet another test chamber (full length) being made incident angle
wire configuration R(outer cylinder) = 1130mm R(outermost wire) = 1111.4mm R(innermost wire) = 168mm R(inner cylinder) = 163mm z-=761.6 mm z+=1561.6 mm 11 degree θ=17 degree θ=30 degree
# of board = 302 Layout of readout board Type B Type A 150mm 230mm Type A 230mm 150mm Type B
Layout of readout board 48 ch/board = 3 layers x 16ch readout board for conical and main part readout board for small cell
Key points of ECL upgrade End caps Barrel One more issue: Material inside ECL changes(reduces)
progress on scintillator KLM by P. Pakhlov ~0.3% of total square dead zone due to inscription of rectangular strips in circle similar to RPC GENERAL LAYOUT • One layer: 75 strips (4 cm width)/sector • 5 segments 1 segment = 15strips • Two orthogonal layer = superlayer • F&B endcap KLM: • Total area ~1400 m2 • 16800 strips • the longest strip 2.8 m; the shortest 0.6 m • WLS fiber in each strip • SiPM at one fiber end • mirrored far fiber end <1% of total square dead zone due to support structure ~3% of total square dead zone due to cables and frugality on short strips (similar to RPC)
by P. Pakhlov MPPC Fermilab (USA) (used in T2K ND) Kharkov (Ukraine) (used in OPERA) Vladimir (Russia) (used in T2K ND) 1 m prototype tested; 100 strips 3m are produced is being transported to ITEP Hamamatsu 1.3×1.3 mm 667 pixels specially designed for T2K 60k produced Fiber CPTA, Moscow 1.25×1.25 mm 720 pixels 10k produced (used in few small experiments) Kuraray Y11 MC No other competative option High efficiency; long atten. length Scintillator 1 m prototype tested (produced 3 years ago); 200 strips 3m ordered; Producer still can not reproduce previous quality 1 m prototype tested (T2K scintillator); 200 strips 3m ordered; To be produced in Dec09-Jan10
Support structure Full size aluminum frame prototype was produced in ITEP, I-profiles net is screwed to the frame filled with plywood mockup of scintillator segments edges. The rigidity of the construction was checked by adding extra weight and trying to rotate the frame
SiPM housing Should fix MPPC to fiber and strip (with 100 micron alignment between MPPC and fiber). Produced after several iterations by Vladimir. It is checked that it provides strong fixation. (Important! MPPC’s pins are made of magnetic material, though the amount of this material is tiny). part II part I • Glue fiber to the housing (part I) • Polish fiber end together with housing edge. • Glue part I to the strip end (no good alignment required). • Put rubber spring and MPPC to part II. • Fasten part II to part I.
Belle II Computing Model Common frameworkfor DAQ and offline based on root I/O Grid-based Distributed Computing Raw Data Storageand Processing Belle II detector MC Production(optional) MC Production and NtupleProduction NtupleAnalysis